UCLA Infection Control Manual

Dr. Andy Wong

The key to preventing micro-organism transfer in the dental laboratory is by breaking the chain of infection at critical exchange points.

Designated areas in the dental laboratory where staff or technicians disinfect incoming and outgoing items are to be established. Place barriers whenever possible to prevent cross contamination.

A. Sterilize all instruments including lab instruments that can withstand high heat. Disinfect all other items.

B. Use individual Instrument Tray Set-Ups whenever possible.

C. Unit Dose Concept: Dispense enough for only one patient when using such items as impression materials, petroleum jelly, waxes, pressure indicator paste, disposable brushes, and orthodontic brackets and wires.

D. Processing and Transfer to the Laboratory. Rinse and disinfect impressions, mould and shade guides, prostheses, and intraoral devices that can be disinfected before transfer to the laboratory. Place casts and prostheses in self-sealing plastic bags or overglove to prevent contact with adjacent materials.

E. All intra-oral items such as impressions, bite registrations, prosthetic and orthodontic appliances shall be cleaned and disinfected in the Dental Treatment Room with an intermediate level disinfectant before manipulation in the laboratory before placement in the patient's mouth.

A. Personnel Protection.

1. All dental lab personnel should receive HBV immunization as all DHCWs.

2. Wear long smocks or smock-type laboratory coats. Change daily or when visibly soiled. Lab coats are not to be worn outside the laboratory or Dental Treatment Facility.

3. Wear face masks, gloves, and eye protection when handling contaminated items and during all disinfection procedures. Eye protection and masks are to be worn whenever polishing, grinding, or working with any rotary instrument. Splash shields shall be used in dental laboratories.

4. Exercise meticulous personal hygiene. Hands are to be washed using a liquid antiseptic soap after de-gloving when working on contaminated cases, and when leaving the laboratory.

5. Refrain from drinking and eating in laboratory areas. Designated eating and drinking areas may be established if space limitations permit. No smoking in lab at any time.

6. No jewelry to be worn on hands and wrists.

B. Case Pans: It is preferable to line and cover case pans with a removable plastic bag when contaminated items are involved. Disinfect all pans following completion of each case. Avoid reusing packing materials.

1. Impressions Received.

   1. If not already disinfected, spray or immerse impressions in a disinfectant before pouring following manufacturer's directions. Place in zip-lock plastic bag or overglove.

   2. Thoroughly debride and rinse impressions under running water before pouring.

   3. When preparing slurry water, use set stone which has not been poured against an impression.

   4. Soak reusable impression trays in pre-soak for designated time, scrub in soapy water, rinse, dry and seal in peel packs for autoclaving.

2. Prostheses Received.

   1. If not already disinfected, clean by scrubbing with a brush and bactericidal soap. Store the brush in a 2% glutaraldehyde solution between use replacing solution at least weekly. Autoclave brushes weekly.

   2. After cleaning, place prostheses in a beaker or container of disinfectant and ultrasonically clean for 10 minutes with cover in place. Beakers used with contaminated prostheses must have solution discarded, and the beaker sterilized or disinfected before re-use. Change solutions daily or whenever visibly soiled. Separate beakers should be used for new and non-contaminated prostheses.

A. Disinfect casts with an appropriate surface disinfectant following manufacturer's instructions.

B. Change and sterilize brushes, rag wheels, and acrylic burs, and discard pumice for each prosthesis.

C. Add a disinfectant to the pumice. Use a different pumice mixing cup for each use.

D. New Prostheses: Work with burs and instruments designated for new prostheses. Disinfect prostheses for designated time using appropriate solution, rinse and store in a sealed plastic bag.

E. Minor adjustments: Do not allow "rush" cases to jeopardize the process of disinfection and separating contaminated from non-contaminated materials, instruments, and supplies.

F. Polishing Area. A unit dose polishing area physically removed from the dental laboratory is the ideal alternative. This contains a polishing unit, and pumice catch pans enclosed in plastic for polishing and grinding agents.

G. Outgoing Casts and Prostheses. Casts and prostheses will be placed in plastic bags for shipping to prevent contamination from packing materials and handling.

H. Disinfection of Laboratory Spaces, Instruments, and Equipment. Maintain separate instruments and materials for use contaminated in a patient's mouth.

1. Change pumice, rag wheels, and brushes used on new prostheses daily.

2. Use two separate polishing lathes if possible; one for new prostheses and one for prostheses that have made intraoral contact.

A. The case reception area and plaster bench.

B. Work areas should be covered with paper that is changed daily or at completion of each contaminated case.

C. Laboratory instruments such as spatulas, knives, and wax carvers following disinfectant manufacturer's instructions.

D. Rubber mixing bowls at completion of each contaminated case.

E. Chucks, switches, handles, tubing, air hoses, and lab handpieces.

F. Model trimmer - spray with disinfectant.

A. Work stations, including exposed equipment, work surfaces, and drawers.

B. Sinks should be emptied, cleaned, and scrubbed with soap or disinfectant, and thoroughly rinsed.

C. Iodophor disinfectants are recommended for surface disinfection of contaminated countertops, walls and floors.

A. Change plaster trap annually at a minimum.

PERIODONTICS INFORMATION CENTER